Michael Brune ended Sierra Club's relationship with Chesapeake when he became executive director in 2010.

An investigation by the Corporate Crime Reporter blog forced the Sierra Club to admit that it secretly had taken millions of dollars from the Chesapeake Energy natural gas company to fund its Beyond Coal campaign from 2007 to 2010 under the leadership of Carl Pope. Time’s Bryan Walsh writes in the complete exposé that Michael Brune ended the relationship when he became executive director in 2010:

Though the group ended its relationship with Chesapeake in 2010—and the Club says it turned its back on an additional $30 million in promised donations—the news raises concerns about influence industry may have had on the Sierra Club’s independence and its support of natural gas in the past. It’s also sure to anger ordinary members who’ve been uneasy about the Club’s relationship with corporations.

In a Sierra Club blog post, Brune explained his response when he became the executive director in 2010: “We cannot accept money from an industry we need to change. Very quickly, the board of directors, with my strong encouragement, cut off these donations and rewrote our gift acceptance policy.”